Carbon fibers have high tensile strength and a high tensile elastic modulus and carbon fiber reinforced plastic formed by solidifying the carbon fibers with resin is a material having high specific strength and a high specific elastic modulus. Therefore, the carbon fibers are widely used as an advanced composite material for aerospace use, use for automobiles, use for civil engineering and construction, use for sporting and leisure goods, and the like.
As a method of manufacturing the carbon fiber reinforced composite material by thermoplastic resin impregnation, there are various methods. For example, one of the methods is a known method in which prepreg impregnated with resin is stacked in a plurality of layers, a blank (stampable sheet) is formed by heating and laminate molding of the layers of prepreg, and a carbon fiber reinforced composite material is formed by reheating and hot press molding of the stampable sheet in a mold.
There is also a joined sheet which is manufactured by respectively disposing thermoplastic resin sheets on upper and lower faces of plain-woven carbon fibers and melting the thermoplastic resin sheets into the carbon fibers by heating and pressurizing the laminated body with hot plates from both sides (see Patent Document 1, for example).
There is also proposed a method of obtaining a carbon fiber reinforced composite material by weaving carbon fibers and thermoplastic resin fibers while blending them (see Patent Document 2, for example).